Please fill out the following information to help in answering your question, and also see tips for posting code snippets. If you don’t provide this information it will take more time to help with your problem!
“Hello fellow Geant4 users, I have a question for the community: I plan to use Geant4 to simulate neutron detection where neutrons interact with matter, produce electrons through reactions, and these electrons are then collected by electrodes to generate measurable currents. As a beginner, could anyone advise if Geant4 provides relevant ready-to-use examples for such simulations?”
Geant4 is primarily designed to simulate energy deposition in materials as particles pass through them, using Monte Carlo-based particle transport. To get started and learn more about the toolkit, I recommend checking out the Beginner course [1] and the Advanced course [2], the video recordings are linked in the corresponding timetables.
Other tools such as Garfield++ are better suited to simulate the electron amplification in the gas.
Thank you very much for your response. I will proceed with the self-study as you suggested, and I hope we can have prompt discussions if any questions arise. Thank you！
Hi, I want to set up a Sensitive Detector in Geant4 to retrieve the time information of particles reaching the collector. How should I configure this? Thank you.
once you have learned how to use a Sensitive Detector following Alvaro’s excellent suggestions you can see that your Hit can store any arbitrary information you like including Globaltime and/or Locatime of the particles.
well, the times are stores as G4double with rather high precision (many digits in for the default seconds). You can do any numeric manipulation/truncation to get them to the unit and precision of your choosing. There is no specific Geant4 way of doing this. Don’t over think it
Thank you for your reply. I spent two weeks quickly getting up to speed with Geant4 and then simulated the example I uploaded earlier. Now, the results from my simulation don’t quite match the expected outcome, as shown in the two figures below. My initial analysis suggests this might be because the decay process is not being accounted for. However, the physics list I added is identical to the one in the example I provided. I’m a bit confused. Do you have any suggestions or insights?
Those specific details of (n,gamma) reactions are probably best described using the newly developed NUDeX dataset and corresponding physicslist. Please have a look at it here:
I had a quick look for an example using it and couldn’t find it. Maybe there is a README file in the dataset that may point you in the right direction?
hello, While reviewing the Geant4 run log, I noticed that kinetic energy is not conserved before and after this hadElastic reaction. Surprisingly, the neutron’s energy actually increases. Could you explain why this happens?
Are you using ParticleHP in your physics list? Did you set a finite temperature for your target volume? If so, you’re seeing one effect of “Doppler smearing” – ParticleHP can take into account the thermal speed of the target atoms, so the nucleus can transfer kinetic energy to the projectile.
I’ve observed an unusual phenomenon: during the decay of Rh-104, why are no gamma particles produced, and why are no excited-state nuclides generated in the reaction process? Is this inherent to Geant4’s operational mechanism?
The printout is telling you that the beta decay was nearly to the ground stage of Pd104. Why would you expect gamma emission since the first excited state is at 51 keV? Both beta decay to the ground state and internal conversion, as a competing process to gamma emission, are low probability but nonzero likelihoods. It is chance you caught one.
Also to avoid confusion later, subsequent x-ray emissions of the Pd104 nucleus are not daughters of the Rh104. They are daughters (secondaries) of the Pd104 or “granddaughters” of the Rh104.
I understand now. Regarding the Rh-103(n,γ) reaction, the output shows five gamma particles at different energies along with excited-state Rh-104 products. Do these five gamma rays carry specific physical significance?
Could you tell me which physical process in the G4NEUTRONXS database is called to generate 104mRh? I’ve tried the following two processes but they didn’t produce it:
G4NEUTRONXS >20 MeV G4NeutronElasticXS
G4NEUTRONXS >20 MeV G4NeutronInelasticXS
Here, a macro for example Hadr03 and its printout, showing the production of 104mRh.
The production rate is rather small : only 326 104mRh for 10000 incident neutrons.
